Highly flowable 1-butene polymer and process for producing the same

Abstract

A 1-butene polymer satisfying the following (1), (2) and either (3) or (3′): a process for producing the polymer; a resin modifier comprising the polymer; and a hot-melt adhesive containing the polymer. (1) The intrinsic viscosity [η] as measured in tetralin solvent at 135° C. is 0.01 to 0.5 dL/g. (2) The polymer is a crystalline resin having a melting point (Tm-D) of 0 to 100° C., the melting point being defined as the top of the peak observed on the highest-temperature side in a melting endothermic curve obtained with a differential scanning calorimeter (DSC) in a test in which a sample is held in a nitrogen atmosphere at −10° C. for 5 min and then heated at a rate of 10° C./min. (3) The stereoregularity index {(mmmm)/(mmrr+rmmr)} is 30 or lower. (3′) The mesopentad content (mmmm) determined from a nuclear magnetic resonance (NMR) spectrum is 68 to 73%.

1. A 1-butene-based resin modifier comprising a high-fluidity 1-butene-based polymer satisfying the following requirements (1), (2), and (3):
 (1) has an intrinsic viscosity [η] of 0.01 to 0.5 dL/g as measured in a tetralin solvent at 135° C.; 
 (2) is a crystalline resin having a melting point (Tm-D) of 0 to 100° C., the melting point being defined as a top of a peak observed on a highest-temperature side in a melting endothermic curve obtained by a differential scanning calorimeter (DSC) when a sample is held in a nitrogen atmosphere at −10° C. for 5 min. and then heated at a temperature rise rate of 10° C/min.; and 
 (3) has a stereoregularity index {(mmmm)/(mmrr+rmmr)} of 30 or lower, produced by a process comprising: 
 homopolymerizing 1-butene, or copolymerizing 1-butene with ethylene and/or a C 3  to C 20  α-olefin except for 1-butene, in the presence of a polymerization catalyst comprising: 
 (A) a transition metal compound having as a ligand, a double crosslinking type biscyclopentadienyl derivative represented by the following general formula (II): 
 
       
         
           
           
               
               
           
         
         wherein M is a metal element belonging to Groups 3 to 10 or lanthanoid of the Periodic Table; 
         X 1  is a ligand that forms a σ-bond with the proviso that when a plurality of X 1  groups are present, these X 1  groups may be the same or different from each other and may be cross-linked with the other X 1  or Y 1 ; 
         Y 1  is a Lewis base with the proviso that when a plurality of Y 1  groups are present, these Y 1  groups may be the same or different and may be cross-linked with the other Y 1  group or X 1 ; 
         R 4  and R 5  are independently a hydrogen atom, a halogen atom, a C 1  to C 20  hydrocarbon group, a C 1  to C 20  halogen-containing hydrocarbon group, a silicon-containing group or a hetero atom-containing group, and R 6  and R 7  as well as R 8  and R 9  are bonded to each other to form a ring; 
         A 1  and A 2  are divalent cross-linking groups which may be the same or different from each other, and are independently a C 1  to C 20  halogen-containing hydrocarbon group, a silicon-containing group, a germanium-containing group, a tin-containing group, —O—, —CO—, —S—, —SO 2 —, —Se—, —NR 1 —, —PR 1 —, —P(O)R 1 —, —BR 1 — or —AlR 1 — wherein R 1  is a hydrogen atom, a halogen atom, or a C 1  to C 20  halogen-containing hydrocarbon group; 
         q is an integer of 1 to 5 given by the formula: 
         [(valence of M)−2]; and 
         r is an integer of 0 to 3; and 
         (B) at least one component selected from the group consisting of (B-1) a compound capable of forming an ionic complex by reacting with said transition metal compound (A), and (B-2) aluminoxane. 
       
     
     
       2. The 1-butene-based resin modifier according to  claim 1 , which has an intrinsic viscosity of 0.1 to 0.5 dL/g. 
     
     
       3. The 1-butene-based resin modifier according to  claim 1 , wherein the 1-butene-based polymer has a melting point of 0 to 80° C. 
     
     
       4. The 1-butene-based resin modifier according to  claim 1 , wherein the 1-butene-based polymer has a stereoregularity index of 20 or lower. 
     
     
       5. The 1-butene-based resin modifier according to  claim 1 , wherein the 1-butene-based polymer has a mesopentad fraction (mmmm) of 20 to 90%. 
     
     
       6. The 1-butene-based resin modifier according to  claim 1 , wherein the 1-butene-based polymer has 1,4-insertion portions in an amount of 5% or lower. 
     
     
       7. The 1-butene-based resin modifier according to  claim 1 , wherein the 1-butene-based polymer has a molecular weight distribution (Mw/Mn) of 4 or lower. 
     
     
       8. The 1-butene-based resin modifier according to  claim 1 , wherein the 1-butene-based polymer has a weight-average molecular weight of 10,000 to 100,000 as measured by GPC. 
     
     
       9. The 1-butene-based resin modifier according to  claim 1 , wherein the 1-butene-based polymer has a tensile modulus of 500 MPa or lower. 
     
     
       10. The 1-butene-based resin modifier according to  claim 1 , wherein the polymer is a random copolymer, and the content of structural units derived from 1-butene in the copolymer is 50 mol% or higher. 
     
     
       11. The 1-butene-based resin modifier according to  claim 10 , wherein the copolymer has a randomness index of 1 or less as determined from α-olefin chains according to the follow formula:
   R=4[αα][BB]/[αB] 2  
 
 wherein [αα] represents an α-olefin chain fraction; [BB] represents a butene chain fraction; and [αB] represents an α-olefin-butene chain fraction. 
 
     
     
       12. A hot melt adhesive comprising a high-fluidity 1-butene-based polymer satisfying the following requirements (1), (2), and (3′):
 (1) has an intrinsic viscosity [η] of 0.25 to 0.5 dL/g as measured in a tetralin solvent at 135° C.; 
 (2) is a crystalline resin having a melting point (Tm-D) of 0 to 100° C., the melting point being defined as a top of a peak observed on a highest-temperature side in a melting endothermic curve obtained by a differential scanning calorimeter (DSC) when a sample is held in a nitrogen atmosphere at −10° C. for 5 min. and then heated at a temperature rise rate of 10° C./min,; and 
 (3′) has a mesopentad fraction (mmmm) of 68 to 73% as determined from a nuclear magnetic resonance (NMR) spectrum, 
 produced by a process comprising: 
 homopolymerizing 1-butene, or copolymerizing 1-butene with ethylene and/or a C 3  to C 20  α-olefin except for 1-butene, in the presence of a polymerization catalyst comprising: 
 (A) a transition metal compound having as a ligand, a double crosslinking type biscyclopentadienyl derivative represented by the following general formula (II): 
 
       
         
           
           
               
               
           
         
         wherein M is a metal element belonging to Groups 3 to 10 or lanthanoid of the Periodic Table; 
         X 1  is a ligand that forms a a-bond with the proviso that when a plurality of X 1  groups are present, these X 1  groups may be the same or different from each other and may be cross-linked with the other X 1  or Y 1 ; 
         Y 1  is a Lewis base with the proviso that when a plurality of Y 1  groups are present, these Y 1  groups may be the same or different and may be cross-linked with the other Y 1  group or X 1 ; 
         R 4  and R 5  are independently a hydrogen atom, a halogen atom, a C 1  to C 20  hydrocarbon group, a C 1  to C 20  halogen-containing hydrocarbon group, a silicon-containing group or a hetero atom-containing group, and R 6  and R 7  as well as R 8  and R 9  are bonded to each other to form a ring; 
         A 1  and A 2  are divalent cross-linking groups which may be the same or different from each other, and are independently a C 1  to C 20  halogen-containing hydrocarbon group, a silicon-containing group, a germanium-containing group, a tin-containing group, —O—, —CO—, —S—, —SO 2 —, —Se—, —NR 1 —, —PR 1 —, —P(O)R 1 —, —BR 1 — or —AIR 1 — wherein R 1  is a hydrogen atom, a halogen atom, or a C 1  to C 20  halogen-containing hydrocarbon group; 
         q is an integer of 1 to 5 given by the formula: 
         [(valence of M)−2]; and 
         r is an integer of 0 to 3; and 
         (B) at least one component selected from the group consisting of (B-1) a compound capable of forming an ionic complex by reacting with said transition metal compound (A), and (B-2) aluminoxane. 
       
     
     
       13. The hot melt adhesive according to  claim 12 , wherein the 1-butene-based polymer has an intrinsic viscosity of 0.3 to 0.5 dL/g. 
     
     
       14. The hot melt adhesive according to  claim 12 , wherein the 1-butene-based polymer has a melting point of 0 to 80° C. 
     
     
       15. The hot melt adhesive according to  claim 12 , wherein the 1-butene-based polymer contains 1,4-insertion portions in an amount of 5% or lower. 
     
     
       16. The hot melt adhesive according to  claim 2 , wherein the 1-butene-based polymer has a molecular weight distribution (Mw/Mn) of 4 or lower. 
     
     
       17. The hot melt adhesive according to  claim 12 , wherein the 1-butene-based polymer has a weight-average molecular weight of 10,000 to 100,000 as measured by GPC. 
     
     
       18. The hot melt adhesive according to  claim 12 , wherein the 1-butene-based polymer has a tensile elongation at break of 100% or higher as measured in a tensile test according to JIS K-7113 and a zero-shear viscosity η 0  of less than 300 Pa·s. 
     
     
       19. The hot melt adhesive according to  claim 12 , wherein the polymer is a random copolymer, and the content of structural units derived from 1-butene in the copolymer is 50 mol% or higher. 
     
     
       20. The hot melt adhesive according to  claim 19 , wherein the copolymer has a randomness index of 1 or less as determined from α-olefin chains according to the follow formula:
   R=4[αα][BB]/[αB] 2  
 
 wherein [αα] represents an α-olefin chain fraction; [BB] represents a butene chain fraction; and [αB] represents an a-olefin-butene chain fraction.